Seroepidemiology of varicella zoster virus in healthcare workers in Babol, Northern Iran

Varicella zoster virus (VZV) infection is one of the nosocomial infections and healthcare workers (HCWs) are at high risk group who work in the hospital with likelihood of varicella acquisition or transmission. This study evaluated the VZV seroprevalence in this high risk population in Babol, Iran. Serological testing for VZV using enzyme linked immunosorbent assay (ELISA) was performed on 459 HCWs in Ayatollah Rouhani Hospital, Babol, Northern Iran from 2011 to 2012. The questionnaire consisted of age, gender, place of residence, marital status, history of chickenpox, educational level, working experience and risk of exposure. The data were collected and analyzed. The mean age of these subjects was 32.2±1.1 years. Four hundred-sixteen (90.6%) cases were females and 43 (9.4%) were males. The overall positive seroprevalence of VZV was 94.6%. No statistically significant differences were observed between age, gender, place of residence, risk of exposure, marital status, educational level, working experience and seropositivity. The seropositivity of varicella was seen in 278 (95.5%) of 297 cases with positive history and in 30 (81.1%) of 37 cases who did not (p=0.005). The results show that a positive history of VZV is associated with positive seroprevalence but can not be a reliable indicator of the immunity, therefore, serological screening should be considered for all the HCWs. Also, vaccination of susceptible subjects was recommended.